; Copyright (c) 1993-2008 by Richard Kelsey and Jonathan Rees. See file COPYING.

; Scanning structures and processing package clauses.

; Utility for compile-structures (link/link.scm) and
; ensure-loaded (env/load-package.scm).
;
; Returns a list of all packages reachable from STRUCTS that answer true to
; INCLUDE-THIS-PACKAGE?.

(define (collect-packages structs include-this-package?)
  (let ((package-seen '())
	(structure-seen '())
	(packages '()))
    (letrec ((recur
	      (lambda (structure)
		(if (not (memq structure structure-seen))
		    (begin
		      (set! structure-seen (cons structure structure-seen))
		      (let ((package (structure-package structure)))
			(if (not (memq package package-seen))
			    (begin
			      (set! package-seen (cons package package-seen))
			      (if (include-this-package? package)
				  (begin
				    (for-each recur (package-opens package))
				    (for-each (lambda (name+struct)
						(recur (cdr name+struct)))
					      (package-accesses package))
				    (set! packages (cons package packages))))))))))))
      (for-each recur structs)
      (reverse packages))))

; Walk through PACKAGE's clauses to find the source code.  The relevent
; clauses are:
;   (file name ...)
;   (begin form ...)
;   (define-all-operators)
;   (usual-transforms)
;
; Returns a list of pairs (file . (node1 node2 ...)), a list of names
; of standard transforms, and a boolean value which is true if the package
; is to include definitions of all primitives.

(define (package-source package)
  (let* ((config-file (package-file-name package))
	 (dir (if config-file
		  (file-name-directory config-file)
		  #f)))
    (fold->3 (lambda (clause stuff transforms primitives?)
	       (case (car clause)
		 ((files)
		  (values (read-files (cdr clause) stuff dir package)
			  transforms
			  primitives?))
		 ((begin)
		  (values (cons (cons config-file (cdr clause))
				stuff)
			  transforms
			  primitives?))
		 ((integrate)
		  (set-package-integrate?! package
					   (or (null? (cdr clause))
					       (cadr clause)))
		  (values stuff transforms primitives?))
		 ((optimize)
		  (values stuff transforms primitives?))
		 ((define-all-operators)
		  (values stuff transforms #t))
		 ((usual-transforms)
		  (values stuff
			  (append (cdr clause) transforms)
			  primitives?))
		 (else
		  (error "unrecognized define-structure keyword"
			 clause))))
	     (reverse (package-clauses package))
	     '() '() #f)))

; Also prints out the filenames (courtesy of READ-FORMS).

(define (read-files all-files stuff dir package)
  (force-output (current-output-port))		; just to be nice
  (fold (lambda (filespec stuff)
	  (let ((file (namestring filespec
				  dir
				  *scheme-file-type*)))
	    (display #\space (current-noise-port))
	    (cons (cons file (read-forms file package #f))
		  stuff)))
	(reverse all-files)
	stuff))

(define (package-optimizer-names package)
  (if (package-integrate? package)
      (let ((opts (apply append
			 (map cdr (filter (lambda (clause)
					    (eq? (car clause) 'optimize))
					  (package-clauses package))))))
	(reduce (lambda (name opts)
		  (if (memq name opts)
		      opts
		      (cons name opts)))
		opts
		'()))
      '()))

(define (check-structure structure)
  (let ((undefined '()))
    (for-each-export
         (lambda (name want-type binding)
	   (if (binding? binding)
	       (let ((have-type (binding-type binding)))
		 (if (not (compatible-types? have-type want-type))
		     (warn "Type in interface doesn't match binding"
			   name
			   `(binding: ,(type->sexp have-type #t))
			   `(interface: ,(type->sexp want-type #t))
			   structure)))
	       (set! undefined (cons name undefined))))
	 structure)
    (if (not (null? undefined))
	(warn "Structure has undefined exports"
	      structure
	      undefined))))

